MSMA Antagonizes Glyphosate and Glufosinate Efficacy on Broadleaf and Grass Weeds

Abstract

Field and greenhouse studies were conducted to investigate the compatibility of MSMA in a tank mixture with glyphosate or glufosinate for broadleaf and grass weed control. Glyphosate, glufosinate, and MSMA were evaluated at 0.5×, 1×, and 2× rates, with 1× rates of 0.84 kgae/ha, 0.5 kgai/ha, and 2.2 kgai/ha, respectively. Glyphosate and glufosinate provided similar levels of control for most weed species and were often more efficacious than MSMA alone. Glyphosate controlled Palmer amaranth better than glufosinate. Glufosinate controlled hemp sesbania, pitted morningglory, and ivyleaf morningglory better than glyphosate at one location. Weed control was not improved with the addition of MSMA to glyphosate or glufosinate when compared with either herbicide alone. MSMA antagonized glyphosate efficacy on barnyardgrass, browntop millet, hemp sesbania, Palmer amaranth, and redroot pigweed. MSMA antagonized glufosinate efficacy on browntop millet, hemp sesbania, ivyleaf morningglory, johnsongrass, Palmer amaranth, pitted morningglory, prickly sida, redroot pigweed, and velvetleaf. Antagonism of glyphosate or glufosinate by MSMA was often overcome by applying the 2× rate of either herbicide alone. MSMA is not a compatible tank-mixture partner with glyphosate or glufosinate for weed control in cotton.

Weed Control and Crop Response to Glufosinate Applied to ‘PHY 485 WRF’ Cotton

“…by glufosinate has been reported previously (Culpepper et al 2000;Norris et al 2002;Wilson et al 2007). As in previous research (Corbett et al 2004;Koger et al 2007), glyphosate was less effective than glufosinate on pitted morningglory. Pitted morningglory was controlled 88% late in the season with systems containing two glyphosate applications.…”

“…Although glufosinate is typically less effective than glyphosate on non-GR Palmer amaranth (Koger et al 2007), glufosinate-based systems have been more effective than glyphosate-based systems on GR Palmer amaranth in Georgia and North Carolina (Whitaker and York, unpublished data). The manufacturer of glufosinate recommends POST application of the herbicide only to cotton designated as LibertyLink (Anonymous 2009a).…”

Saflufenacil efficacy on horseweed and its interaction with glyphosate

“…In order to determine the potential for interaction, the expected and observed values were compared at the 0.05 level of significance using Fisher's Protected Least Significant Difference (LSD) test, calculated for the observed data (Wehtje & Walker ; Koger et al . ). If the observed response of a herbicide combination was either significantly lower or greater than the expected value, the combination was declared “antagonistic” or “synergistic”, respectively.…”

Interaction of Glufosinate and <i>Colletotrichum truncatum</i> on Ammonia Levels and Glutamine Synthetase Activity in Hemp Sesbania

“…No pre-or post-emergent herbicide can provide season-long control of hemp sesbania [5]. This weed exhibits some tolerance to glyphosate [N-(phosphonomethyl)glycine] [6] [7] [8], but glufosinate[2-amino-4-(hydroxymethylphosphinyl)butanoic acid] can provide effective control [9] [10]. Glufosinate is the ammonium salt of phosphinothricin (a naturally produced tripeptide), which is the active ingredient of bialaphos derived from non-phytopathogenic species in the genus Streptomyces [11].…”